1. Field of the Invention
The invention relates to disc drive systems, and more specifically to systems and methods preventing invalid data from transfer.
2. Description of the Related Art
Optical discs, widely used due to advantages of large capacity and convenience, include read-only discs such as CD-ROM and DVD-ROM, writeable discs such as CD-R and DVD-R, and rewritable discs such as CD-RW, DVD-RAM and DVD+RW.
Generally, when disc drives transfer data from optical discs to a host computer, the validity of data is verified in terms of error correction and according to defect information of the optical disc, with transfer stopped if the data is invalid. In the case of defective information, the physical target address of optical discs is compared to the defect addresses in a defect list identifying defective sectors of optical discs. If the physical target address matches any of the defect addresses of the defect list, reproduction is interrupted and the pick-up head of the drive seeks correct data with the replacement sector address of the defect list corresponding to the matching defect address. This, however, slows reproduction and degrades system performance. In the case of error correction, before transferring data read from optical discs to the host computer, a code error correction process is performed on the data in a decoder of disc drives according to an error detection code (EDC) of the data. Code error detection process is then followed using an error correction code (ECC) of the data to verify the correction of data. Error correction and detection are repeated until the ECC represents no code error in the data. This, however, lowers system speed. Hence, it is advantageous to obtain a data reproduction method overcoming the above problems.